usb: xhci-plat: Add support for PM suspend and hibernation

Add support for PM suspend and hibernation even when the
connected devices do not support runtime suspend.
In such cases, set the hibernated argument to xhci_resume which
will trigger the reset-resume of the connected root-hubs and the
devices.

Change-Id: I226ed4b0f92f58828b10195aae66b26b8cf18662
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>